Sensor release for a sensor dispensing instrument

ABSTRACT

A sensor dispensing instrument adapted to handle a sensor pack containing a plurality of sensors and to perform a test using one of the sensors. The sensor dispensing instrument includes an outer housing and a mechanical mechanism contained therein for rotating the sensor pack and ejecting one of the sensors from the sensor pack and through a sensor slot on the housing. The sensor dispensing instrument also includes a sensor actuator to engage with a sensor disposed in the sensor slot, and a sensor release that is movable to disengage the sensor actuator from the sensor disposed in the sensor slot and permit the discharge of the sensor.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of the U.S. Provisional Application60/311,758, filed on Aug. 13, 2001, which is hereby incorporated byreference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to a fluid monitoring system,and, more particularly, to a new and improved instrument for handlingmultiple sensors that are used in analyzing blood glucose or otheranalytes contained therein.

2. Description of the Prior Art

People suffering from various forms of diabetes routinely need to testtheir blood to determine the level of blood glucose. The results of suchtests can be used to determine what, if any, insulin or other medicationneeds to be administered. In one type of blood glucose testing system,sensors are used to test a sample of blood.

Such a sensor may have a generally flat, rectangular shape with a frontor testing end and a rear or contact end. The sensor contains biosensingor reagent material that will react with blood glucose. The testing endof the sensor is adapted to be placed into the fluid being tested, forexample, blood that has accumulated on a person's finger after thefinger has been pricked. The fluid is drawn into a capillary channelthat extends in the sensor from the testing end to the reagent materialby capillary action so that a sufficient amount of fluid to be tested isdrawn into the sensor. The fluid then chemically reacts with the reagentmaterial in the sensor with the result that an electrical signalindicative of the blood glucose level in the blood being tested issupplied to contact areas located near the rear or contact end of thesensor.

In order to couple the electrical signals produced at the sensorcontacts to monitoring equipment, the sensors need to be inserted intosensor holders prior to the sensor end being placed into the fluid beingtested. The holders have corresponding mating contact areas that becomecoupled to the contacts on the sensor when the sensor is inserted intothe holder. Consequently, the holders act as an interface between thesensor and monitoring equipment that accumulates and/or analyzes thetest results.

Prior to being used, the sensors need to be maintained at an appropriatehumidity level so as to insure the integrity of the reagent materials inthe sensor. Sensors can be packaged individually in tear-away packagesso that they can be maintained at the proper humidity level. Forinstance, blister type packaging methods could be used. In thisconnection, the packages can include desiccant material to maintain theproper humidity in the package. In order for a person to use anindividual sensor for testing blood glucose, the package must be openedby tearing the seal. Alternatively, some packages require the user toexert force against one side of the package resulting in the sensorbursting or rupturing the foil on the other side. As can be appreciated,the opening of these packages can be difficult. Moreover, once thepackage is opened, the user needs to be sure that the sensor is notdamaged or contaminated as it is being placed into the sensor holder andused to test the blood sample.

U.S. Pat. No. 5,630,986, issued on May 20, 1997, and entitled DispensingInstrument For Fluid Monitoring Sensors (referred to hereinafter as “the'986 patent”), discloses a type of sensor pack with multiple sensors anda testing blood glucose and dispensing instrument for handling thesensors contained in such a sensor pack. In particular, the sensordispensing instrument disclosed in the '986 patent is adapted to receivea sensor pack containing a plurality of blood glucose sensors. Thesensor pack includes a circular base having a plurality of sensorretaining cavities, each of which hold an individual sensor. Each of thesensors has a generally flat, rectangular shape with a front testing endthrough which fluid is drawn so as to react with a reagent material inthe sensor and an opposite rear, contact end.

The sensor instrument disclosed in the '986 patent includes an outerhousing having an upper and a lower case that are pivotable with respectto each other so that the sensor pack can be positioned in the housingon an indexing disk disposed in the housing. With the sensor pack loadedin the housing, a slide latch on a slide actuator disposed on the uppercase of the housing controls whether the movement of the slide actuatorplaces the instrument in a display mode or in a testing mode. Theinstrument is placed into its display mode when the slide latch is movedlaterally and the slide actuator is pushed away from its standbyposition. When in the display mode, a person using the instrument canview data displayed on a display unit in the upper case and/or inputdata into the instrument.

The instrument is in its testing mode when the slide latch is in itsnormal position and the slide actuator is pushed towards its testingposition. As the slide actuator is moved towards its actuated position,the driver with the knife blade thereon moves toward the testingposition of the feed mechanism and the disk drive arm travels in astraight, radially extending groove in the indexing disk such that thedisk is not rotated as the feeding mechanism is moving towards itstesting position. The knife blade is moved towards one of the sensorcavities in the sensor pack and pierces the foil covering the sensorcavity so as to engage the sensor disposed in the cavity. As the slideactuator and the driver are pushed toward the actuated position of theactuator, the knife blade ejects the sensor out from the sensor cavityand into a testing position near the testing end of the sensor housing.

Once the blood analyzing test is completed, the slide actuator is movedin the opposite direction towards its standby position so that thesensor can be removed from the dispensing instrument. The continuedretraction of the driver causes the indexing disk drive arm to travelalong a curvilinearly extending groove in the indexing disk, resultingin the rotation of the indexing disk. The rotation of the indexing diskresults in the sensor pack being rotated so that the next sensor ispositioned in alignment with the knife blade for the next blood glucosetest that is to be performed.

Although the sensor instrument disclosed in the '986 patent overcomesmany of the problems discussed above in connection with the use ofindividual sensors, some users have experienced difficulties in theoperation and/or manipulation of the disclosed sensor instrument. Forexample, users with limited dexterity may find it difficult to remove aused sensor from the device. Because the used sensor contains blood orother fluids, the sensor should be disposed of immediately after thetesting procedure is complete. Moreover, physical handling of the usedsensor should be avoided to prevent the spreading of blood born diseasesor other harmful contaminants. It is therefore desirable that the usedsensor be removed from the device without being grasped or otherwisehandled by the user.

In the device disclosed in the '986 patent, a used sensor is ordinarilydischarged by sliding the slide latch away from the testing end of thedevice and simultaneously tipping the testing end of the devicedownwardly. This requires an awkward manipulation of the device that maybe particularly difficult for users, particularly elderly userssuffering from diabetes, which lack dexterity in their wrist, hand orfingers. As a result, many users may be tempted to grab the end of theused sensor to remove it from the device. It is therefore desirable tohave an improved sensor dispensing instrument that utilizes a simplifiedmethod of discharging used sensors, and can be more easily manipulatedby users with limited dexterity.

In addition, because the slide latch is manipulated during the testingprocedure, and is used to place the device into the display mode, theuser may inadvertently discharge the sensor from the testing positionprior to conducting or completing the blood glucose test. For example,if the user accidentally slides the slide latch away from the testingend of the device during the middle of the testing procedure, the sensormay fall out of the device before the blood glucose test is complete.The user would then need to re-start the testing procedure to load a newsensor into the testing position. It is therefore desirable to have animproved sensor dispensing instrument that is less likely toinadvertently discharge sensors.

BRIEF SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide a new andimproved sensor dispensing instrument for handling the sensors containedin a sensor pack of multiple sensors used in testing blood glucose. Inparticular, objects of the present invention are to provide a new andimproved fluid sensor dispensing instrument handling device having animproved design and mechanism for discharging a sensor following thecompletion of the testing procedure, can be more easily manipulated by auser with limited wrist, hand or finger dexterity, reduces theinadvertent discharge of sensors, and which otherwise overcomes theproblems or limitations discussed above.

In accordance with these and many other objects of the presentinvention, the present invention is embodied in a sensor dispensinginstrument that is adapted to handle a sensor pack containing aplurality of sensors, each of the plurality of sensors being disposed ina sensor cavity on the sensor pack and enclosed by a protective foilcovering. The sensor dispensing instrument is further adapted to performa test using one of the sensors. The sensor dispensing instrumentincludes an outer housing having a front end and a rear end, and asensor slot at the front end of the housing through which one of saidsensors is disposed to conduct the test. The sensor dispensinginstrument also includes a mechanical mechanism that has an indexingdisk for supporting and rotating the sensor pack, an indexing disk drivearm for rotating the indexing disk, a knife blade assembly forpuncturing the foil covering and ejecting one of the sensors from thesensor cavity and through the sensor slot, and a puller handle formoving the indexing disk drive arm and the knife blade assembly. Thesensor dispensing instrument also includes a sensor actuator generallydisposed adjacent to the sensor slot. The sensor actuator is adapted toengage with a sensor disposed in the sensor slot, to connect to contactson the sensor, and to transmit electrical signals between the sensor andan electronics assembly disposed in the outer housing for performing thetest and displaying test results. A sensor release is generally disposedon a surface of the outer housing. The sensor release is movable todisengage the sensor actuator from the sensor disposed in the sensorslot and permit the release or discharge of the sensor.

In the preferred embodiment, the mechanical mechanism also includes amovable disk drive pusher, with the indexing disk drive arm and theknife blade assembly being mounted on the disk drive pusher, and thepuller handle being affixed to the rear end of the disk drive pusher.The sensor actuator is engaged by a front end of the disk drive pusherto cause the sensor actuator to engage the sensor disposed in the sensorslot. The sensor release engages the front end of the disk drive pusherto cause the sensor actuator to disengage from the sensor disposed inthe sensor slot.

In accordance with another aspect of the present invention, the presentinvention is embodied in a method of operating a sensor dispensinginstrument that is adapted to handle a sensor pack containing aplurality of sensors and to perform a test using one of the sensors,wherein the sensor dispensing instrument includes an outer housinghaving a sensor slot through which one of the sensors is disposed toconduct the test, a mechanical mechanism having an indexing disk forsupporting and rotating the sensor pack, an indexing disk drive arm forrotating the indexing disk, a knife blade assembly for puncturing thefoil covering and ejecting one of the sensors from the sensor cavity andthrough the sensor slot, and a puller handle for moving the indexingdisk drive arm and the knife blade assembly, and a sensor release forengaging the drive pusher. The method comprises the steps of: a)grasping said puller handle when the puller handle is in the stand-byposition; b) pulling the puller handle from the stand-by position to theextended position so as to rotate the indexing disk; c) pushing thepuller handle from the extended position to the testing position so asto eject one of said sensors from the sensor cavity and through thesensor slot; d) performing the test by using the sensor disposed in thesensor slot; e) viewing the test results generated by the test on aliquid crystal display; and f) activating the sensor release to move thepuller handle from the testing position to the stand-by position so asto cause the sensor to be released from the sensor slot.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

The present invention, together with the above and other objects andadvantages, can best be understood from the following detaileddescription of the embodiment of the invention illustrated in thedrawing, wherein:

FIG. 1 is a top perspective view of a blood glucose sensor dispensinginstrument embodying the present invention;

FIG. 2 is a bottom perspective view of the blood glucose sensordispensing instrument of FIG. 1;

FIG. 3 is a perspective view of the blood glucose sensor dispensinginstrument of FIG. 1 in the opened position showing the insertion of asensor pack;

FIG. 4 is a perspective view of the blood glucose sensor dispensinginstrument of FIG. 1 in the opened position showing a sensor pack loadedonto the indexing disk;

FIG. 5 is a top perspective view of the blood glucose sensor dispensinginstrument of FIG. 1 shown with the button door in the open position;

FIG. 6 is a top perspective view of the blood glucose sensor dispensinginstrument of FIG. 1 with the disk drive pusher in the extendedposition;

FIG. 7 is a top perspective view of the blood glucose sensor dispensinginstrument of FIG. 1 with the disk drive pusher in the testing positionwith a sensor projecting from the sensor opening;

FIG. 8 is a top perspective view of a sensor for use with blood glucosesensor dispensing instrument of FIG. 1;

FIG. 9 is an exploded perspective view of a sensor pack for use withblood glucose sensor dispensing instrument of FIG. 1 showing theprotective foil separated from the base portion of the sensor pack;

FIG. 10 is an exploded perspective view of the component sub-assembliesof blood glucose sensor dispensing instrument of FIG. 1;

FIG. 11 is an exploded perspective view of the component parts of theupper case sub-assembly of the blood glucose sensor dispensinginstrument of FIG. 1;

FIG. 12 is an exploded perspective view of the component parts of thelower case sub-assembly of the blood glucose sensor dispensinginstrument of FIG. 1;

FIG. 13 is an exploded top perspective view of the component parts ofthe disk drive mechanism and indexing disk sub-assembly of the bloodglucose sensor dispensing instrument of FIG. 1;

FIG. 14 is an exploded bottom perspective view of the component parts ofthe disk drive mechanism and indexing disk sub-assembly of the bloodglucose sensor dispensing instrument of FIG. 1;

FIG. 15 is an exploded perspective view of the component parts of thebattery tray sub-assembly of the blood glucose sensor dispensinginstrument of FIG. 1;

FIG. 16 is an exploded perspective view of the component parts of theelectronics assembly of the blood glucose sensor dispensing instrumentof FIG. 1;

FIG. 17 is a top perspective view of the electronics sub-assembly of theblood glucose sensor dispensing instrument of FIG. 1; and

FIG. 18 is a bottom perspective view of the electronics sub-assembly ofthe blood glucose sensor dispensing instrument of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

Referring now more specifically to the drawings, therein is disclosed ablood glucose sensor dispensing instrument generally designated by thereference numeral 10 and embodying the present invention. The sensordispensing instrument 10 includes an outer housing 12 having an uppercase 18 and a lower case 24, the lower case 24 pivoting on the uppercase 18. The upper case 18 is pivotable with respect to the lower case24 in a clamshell fashion so that a sensor pack 300 (see FIGS. 3 and 4)can be positioned on an indexing disk 30 within the housing 12. With thesensor pack 300 so loaded in the housing 12, a puller handle 32extending from a rear end 22 of the upper case 18 of the housing 12 canbe moved to activate a disk drive mechanism, generally designated by thenumeral 34 (see FIG. 10), to load a sensor 302 into a testing positionon the front end 14 of the housing 12 (see FIG. 3).

It should be noted that the sensor dispensing instrument 10 of thepresent invention incorporates components that are similar in designand/or function as those described in U.S. Pat. No. 5,630,986, issuedMay 20, 1997, and entitled Dispensing Instrument For Fluid MonitoringSensors. The contents of this patent are hereby incorporated byreference to avoid the unnecessary duplication of the description ofthese similar components.

The sensor pack 300 utilized by the sensor dispensing instrument 10 isof the type described in U.S. Pat. No. 5,575,403, issued Nov. 19, 1996,and entitled Dispensing Instrument For Fluid Monitoring Sensors, thecontents of which are hereby incorporated by reference. In general, andas shown in FIGS. 8 and 9, the sensor pack 300 is adapted to house tensensors 302, with one of the ten sensors 302 in each of ten separatesensor cavities 304. Each of the sensors 302 has a generally flat,rectangular shape extending from a front or testing end 306 to a backend 308. The front end 306 is angled so that it will puncture anunsevered portion of the protective foil 310 overlying the sensor cavity304 as the sensor 302 is being forced out of the sensor cavity 304 by aknife blade 36 (to be described below). The front end 306 is alsoadapted to be placed into blood that is being analyzed. The back end 308of the sensor 302 includes a small notch 312 that is engaged by theknife blade 36 as the knife blade 36 ejects the sensor 302 from thesensor cavity 304. Contacts 314 near the back end 308 of the sensor 302are adapted to mate with metal contacts 38 on a sensor actuator 40 (tobe described below) when the sensor 302 is in the testing positionillustrated in FIG. 7. As a result, the sensor 302 is coupled to theelectronic circuitry on the circuit board assembly 42 so thatinformation generated in the sensor 302 during testing can be stored,analyzed and/or displayed.

As best seen in FIG. 8, each sensor 302 is provided with a capillarychannel 316 that extends from the front or testing end 306 of the sensor302 to biosensing or reagent material disposed in the sensor 302. Whenthe testing end 306 of the sensor 302 is placed into fluid (for example,blood that is accumulated on a person's finger after the finger has beenpricked), a portion of the fluid is drawn into the capillary channel 316by capillary action. The fluid then chemically reacts with the reagentmaterial in the sensor 302 so that an electrical signal indicative ofthe blood glucose level in the blood being tested is supplied to thecontacts 314, and subsequently transmitted through the sensor actuator40 to the circuit board assembly 42.

As best seen in FIG. 9, the sensor pack 300 comprises a circularlyshaped base portion 318 covered by a sheet of protective foil 310. Thesensor cavities 304 are formed as depressions in the base portion 318,with each of the sensor cavities 304 adapted to house an individualsensor 302. Each of the sensor cavities 304 has an inclined or slopedsupport wall 320 to guide the sensor 302 as the sensor 302 is ejectedthrough the foil 310 and out of the sensor cavity 304.

Each of the sensor cavities 304 is in fluid communication with adesiccant cavity 322 formed by a small depression in the base portion318. Desiccant material is disposed in each of the desiccant cavities322 in order to insure that the sensor cavities 304 are maintained at anappropriate humidity level to preserve the reagent material in thesensor 302.

Notches 324 are formed along the outer peripheral edge of the baseportion 318. The notches 324 are configured to engage pins 44 on theindexing disk 30 so that the sensor cavities 304 are in proper alignmentwith the indexing disk 30 when the sensor pack 300 is loaded into thesensor dispensing instrument 10. As will be explained in greater detailbelow, the sensor cavities 304 must be aligned with the knife slots 46in the indexing disk 30 to permit the knife blade 36 to engage, ejectand push one of the sensors 302 into a testing position on the front end14 of the housing 12.

The sensor pack 300 further comprises a conductive label 326 on thecentral portion of the base portion 318. As will be explained below, theconductive label 326 provides calibration and production informationabout the sensor pack 300 that can be sensed by calibration circuitry inthe sensor dispensing instrument 10.

To operate the sensor dispensing instrument 10, the puller handle 32 isfirst manually pulled from a standby position (FIG. 1) adjacent the rearend 16 of the housing 12 to an extended position (FIG. 6) away from therear end 16 of the housing 12. The outward movement of the puller handle32 causes the disk drive mechanism 34 to rotate the sensor pack 300 andplace the next sensor 302 in a standby position prior to being loadedinto a testing position. The outward movement of the puller handle 32also causes the sensor dispensing instrument 10 to turn ON (i.e., theelectronic circuitry on the circuit board assembly 42 is activated).

As will be described in greater detail below, the disk drive mechanism34 includes a disk drive pusher 48 on which an indexing disk drive arm50 is mounted (see FIGS. 13 and 14). The indexing disk drive arm 50comprises a cam button 52 disposed at the end of a plate spring 54. Thecam button 52 is configured to travel in one of a plurality ofcurvilinearly extending grooves 56 on the upper surface of the indexingdisk 30. As the puller handle 32 is manually pulled from a standbyposition adjacent the rear end 16 of the housing 12 to an extendedposition away from the rear end 16 of the housing 12, the disk drivepusher 48 is pulled laterally towards the rear end 22 of the upper case18. This causes the cam button 52 on the indexing disk drive arm 50 totravel along one of the curvilinearly extending grooves 56 so as torotate the indexing disk 30. The rotation of the indexing disk 30 causesthe sensor pack 300 to be rotated so that the next one of the sensorcavities 304 is placed in a standby position.

The puller handle 32 is then manually pushed inwardly from the extendedposition (FIG. 6) back past the standby position (FIG. 1) and into atesting position (FIG. 7). The inward movement of the puller handle 32causes the disk drive mechanism 34 to remove a sensor 302 from thesensor pack 300 and place the sensor 302 into a testing position on thefront end 14 of the housing 12.

As will be described in greater detail below, the disk drive mechanism34 includes a knife blade assembly 58 that is pivotally mounted to thedisk drive pusher 48 (see FIGS. 13 and 14). As the puller handle 32 ismanually pushed from the extended position to the testing position, thedisk drive pusher 48 is pushed laterally towards the testing or frontend 20 of the upper case 18. This causes the knife blade assembly 58 topivot downwardly so that a knife blade 36 on the end of the knife bladeassembly 58 pierces a portion of the protective foil 310 covering one ofthe sensor cavities 304 and engages the sensor 302 in the sensor cavity304. As the disk drive pusher 48 continues to move towards the front end20 of the upper case 18, the knife blade assembly 58 forces the sensor302 out of the sensor cavity 304 and into a testing position at thefront end 14 of the housing 12.

While the disk drive pusher 48 is being pushed from the extendedposition to the testing position, the cam button 52 on the indexing diskdrive arm 50 travels along one of the radially extending grooves 60 toprevent the indexing disk 30 from rotating. Similarly, while the diskdrive pusher 48 is being pulled from the standby position to theextended position, the knife blade assembly 58 is in a retractedposition so as to not interfere with the rotation of the indexing disk30.

After the sensor 302 has been completely ejected from the sensor cavity304 and pushed into a testing position projecting out from the front end14 of the housing 12, the disk drive pusher 48 engages and forces asensor actuator 40 against the sensor 302 to thereby maintain the sensor302 in the testing position. The sensor actuator 40 engages the sensor302 when the puller handle 32 is pushed past the standby position andinto the testing position. The sensor actuator 40 couples the sensor 302to an electronics assembly 62 disposed in the upper case 18. Theelectronics assembly 62 includes a microprocessor or the like forprocessing and/or storing data generated during the blood glucose testprocedure, and displaying the data on a liquid crystal display 64 in thesensor dispensing instrument 10.

Once the blood analyzing test is completed, a button release 66 on theupper case 18 is depressed so as to disengage the sensor actuator 40 andrelease the sensor 302. Depressing the button release 66 causes the diskdrive pusher 48 and the puller handle 32 to move from the testingposition back to the standby position. At this point, the user can turnthe sensor dispensing instrument 10 OFF by depressing the button 96 onthe upper case 18, or by allowing the sensor dispensing instrument 10automatically turn OFF pursuant a timer on the electronics assembly 62.

As seen in FIGS. 1-7 and 10-12, the upper case 18 and the lower case 24of the sensor dispensing housing 12 are complementary, generally ovalshaped hollow containers that are adapted to be pivoted with respect toeach other about pivot pins 68 extending outwardly in the rear end 22 ofthe upper case 18 into pivot holes 70 in a rear section 28 of the lowercase 24. The upper case 18 and the lower case 24 are maintained in theirclosed configuration by a latch 72 that is pivotally mounted in a frontsection 26 of the lower case 24 by pins 74 that extend inwardly intopivot holes 76 in the latch 72 (see FIG. 12). The latch 72 has recesses78 that are configured to mate with hooks 80 on the upper case 18 tosecure the upper case 18 and the lower case 24 in their closedconfiguration. The latch 72 is biased in a vertical or closed positionby a latch spring 82. The ends 84 of the latch spring 82 are secured inslots 86 on the inside of the lower case 24. When the latch 72 ispivoted against the biasing force of the latch spring 82, the hooks 80on the upper case 18 disengage from the recesses 78 to permit the uppercase 18 and the lower case 24 to open.

As seen in FIGS. 1, 5-7 and 10-11, the upper case 18 includes arectangular opening 30 through which a liquid crystal display 64 isvisible below. The liquid crystal display 64 is visible through adisplay lens 88 that is affixed to upper surface of the upper case 18.In the preferred embodiment shown, the display lens 88 has an opaqueportion 90 and a transparent portion 92, the transparent portion 92being coincident with the display area of liquid crystal display 64. Theliquid crystal display 64 is a component of the electronics assembly 62,and is coupled to the circuit board assembly 42 via elastomericconnectors 94 (see FIG. 16). The liquid crystal display 64 displaysinformation from the testing procedure and/or in response to signalsinput by the buttons 96 on the upper case 18. For example, the buttons96 can be depressed to recall and view the results of prior testingprocedures on the liquid crystal display 64. As best seen in FIG. 11,the buttons 96 are part of a button set 98 that is attached to the uppercase 18 from below so that the individual buttons 96 project upwardlythrough button openings 100 in the upper case 18. When pressed, thebuttons 96 are electrically connected to the circuit board assembly 42.

As best seen in FIGS. 1, 5 and 11, a button door 102 is pivotallyconnected to the upper case 18 by a pair of pins 104 projectingoutwardly from either side of the button door 102 that engage holes 106on the side walls of the upper case 18. The button door 102 alsocomprises a pair of ears 108 that fit into recesses 110 in the sidewalls of the upper case 18 when the button door 102 is closed. The ears108 extend slightly beyond the side walls of the upper case 18 so thatthey can be grasped by the user to open the button door 102. A pivotedge 112 of the button door 102 engages a tab 114 on the upper surfaceof the upper case 18. The tab 114 rubs against the pivot edge 112 insuch a manner so as to bias the button door 102 in either a closed orfully open position. In the preferred embodiment shown, the button door102 has an opening 116 that permits one of the buttons 96 (e.g., anOn/Off button) to be accessed when the button door 102 is closed (seeFIG. 1). This permits dedicated, but seldom or lesser used buttons 96 tobe concealed underneath the button door 102, thereby simplifying thelearning curve and daily operation of the sensor dispensing instrument10 for the user.

The upper case 18 also contains an opening 118 for the button release66, which projects upwardly through the upper case 18. As will bedescribed in more detail below, the button release 66 is depressed todisengage the sensor actuator 40 and release a sensor 302 from thetesting position.

The upper case 18 also contains an opening 120 for a battery trayassembly 122. The battery tray assembly 122 includes a battery tray 124in which a battery 126 is disposed. The batter tray assembly 122 isinserted into the opening 120 in the side of the upper case 18. When soinserted, the battery 126 engages battery contacts 128 and 130 on thecircuit board assembly 42 so as to provide power for the electronicswithin the instrument 10, including the circuitry on the circuit boardassembly 42 and the liquid crystal display 64. A tab 132 on the lowercase 24 is configured to engage a slot 134 in the battery tray assembly122 so as to prevent the battery tray assembly 122 from being removedfrom the sensor dispensing instrument 10 when the upper case 18 and thelower case 24 are in the closed configuration.

An electronics assembly 62 is affixed to the upper inside surface of theupper case 18. As best seen in FIGS. 16-18, the electronics assembly 62comprises a circuit board assembly 42 on which various electronics andelectrical components are attached. A positive battery contact 128 and anegative battery contact 130 are disposed on the bottom surface 136(which is the upwardly facing surface as viewed in FIGS. 16 and 18) ofthe circuit board assembly 42. The battery contacts 128 and 130 areconfigure to electrically connect with the battery 126 when the batterytray assembly 122 is inserted into the side of the upper case 18. Thebottom surface 136 of the circuit board assembly 42 also includes acommunication interface 138. The communication interface 138 permits thetransfer of testing or calibration information between the sensordispensing instrument 10 and another device, such as a personalcomputer, through standard cable connectors (not shown). In thepreferred embodiment shown, the communication interface 138 is astandard serial connector. However, the communication interface 138could alternatively be an infra-red emitter/detector port, a telephonejack, or radio frequency transmitter/receiver port. Other electronicsand electrical devices, such as memory chips for storing glucose testresults or ROM chips for carrying out programs are likewise included onthe bottom surface 136 and the upper surface 140 of the circuit boardassembly 42.

A liquid crystal display 64 is affixed to the upper surface 140(upwardly facing surface in FIG. 17) of the circuit board assembly 42.The liquid crystal display 64 is held by a snap-in display frame 142.The snap-in display frame 142 includes side walls 144 that surround andposition the liquid crystal display 64. An overhang 146 on two of theside walls 144 holds the liquid crystal display 64 in the snap-indisplay frame 142. The snap-in display frame 142 includes a plurality ofsnap fasteners 148 that are configured to engage mating holes 150 on thecircuit board assembly 42. The liquid crystal display 64 is electricallyconnected to the electronics on the circuit board assembly 42 by a pairof elastomeric connectors 94 disposed in slots 152 in the snap-indisplay holder 142. The elastomeric connectors 94 generally comprisealternating layers of flexible conductive and insulating materials so asto create a somewhat flexible electrical connector. In the preferredembodiment shown, the slots 152 contain a plurality of slot bumps 154that engage the sides of the elastomeric connectors 94 to prevent themfrom falling out of the slots 152 during assembly.

As set forth in detail in the U.S. Patent Application entitle Snap-inDisplay Frame, which is being filed together with the presentapplication, the snap-in display frame 142 eliminates the screw-typefasteners and metal compression frames that are typically used toassemble and attach a liquid crystal display 64 to an electronic device.In addition, the snap-in display frame 142 also permits the liquidcrystal display 64 to be tested prior to assembling the liquid crystaldisplay 64 to the circuit board assembly 42.

The button set 98 also mates to the upper surface 140 of the circuitboard assembly 42. As mentioned above, the button set 98 comprisesseveral individual buttons 96 that are depressed to operate theelectronics of the sensor dispensing instrument 10. For example, thebuttons 96 can be depressed to activate the testing procedure of thesensor dispensing instrument 10. The buttons 96 can also be depressed torecall and have displayed on the liquid crystal display 64 the resultsof prior testing procedures. The buttons 96 can also be used to set anddisplay date and time information, and to activate reminder alarms whichremind the user to conduct a blood glucose test according to apredetermined schedule. The buttons 96 can also be used to activatecertain calibration procedures for the sensor dispensing instrument 10.

The electronics assembly 62 further comprises a pair of surface contacts139 on the bottom surface 136 of the circuit board assembly 42 (seeFIGS. 16 and 18). The surface contacts 139 are configured so as to becontacted by one or more fingers 143 on the cover mechanism 188, whichin turn are configured to be engaged by a pair of ramp contacts 141 onthe disk drive pusher 48 (see FIGS. 6 and 13). Movement of the pullerhandle 32 causes the ramp contacts 141 to push the fingers 143 intocontact with one or both of the surface contacts 139 so as tocommunicate the position of the puller handle 32 to the electronicsassembly 62. In particular, movement of the puller handle 32 from thestand-by or testing positions to the extended position will turn thesensor dispensing instrument ON. In addition, if the housing 12 isopened while the puller handle 32 is in the extended position, an alarmwill be activated to warn the user that the knife blade 36 may be in theextended position.

It should be noted that the design and configuration of the electronicsassembly 62 permits the assembly and testing of the electronics andelectrical components prior to assembly of the electronics assembly 62to the upper case 18 of the sensor dispensing instrument 10. Inparticular, the liquid crystal display 64, the button set 98, thebattery contacts 128 and 130, and the other electronics and electricalcomponents can each be assembled to the circuit board assembly 42 andtested to verify that these components, and the electrical connectionsto these components, are working properly. Any problem or malfunctionidentified by the testing can then be corrected, or the malfunctioningcomponent can be discarded, prior to assembling the electronics assembly62 to the upper case 18 of the sensor dispensing instrument 10.

As mentioned above, the sensor dispensing instrument 10 includescalibration circuitry for determining calibration and productioninformation about the sensor pack 300. As best seen in FIG. 12, thecalibration circuitry comprises a flex circuit 156 located in the lowercase 24. The flex circuit 156 is held in position in the lower case 24by an autocal disk 158 that is connected to the rear section 28 of thelower case 24 by a pair of pins 160. The autocal disk 158 has a raisedcentral portion 162 configured to engage the sensor cavities 304 on thesensor pack 300 so as to hold the sensor pack 300 against the indexingdisk 30. The autocal disk 158 also has an open area 164 located betweenthe pins 160 to expose contacts 166 on the flex circuit 156.

The flex circuit 156 comprises a plurality of probes 168 that extendupwardly from the flex circuit 156 through holes 170 in the inner regionof the autocal disk 158. These probes 168 are connected to the contacts166 on the end of the flex circuit 156. When the sensor dispensinginstrument 10 is closed with the lower case 24 latched to the upper case18, the probes 168 make contact with a conductive label 326 on thesensor pack 300 being used in the sensor dispensing instrument 10. Afoam pad 172 is positioned below the flex circuit 156 to provide abiasing force to assure that the probes 168 press against the conductivelabel 326 with a force sufficient to make an electrical connection. Thefoam pad 172 also provides a cushioning force so that the probes 168 canmove independently with respect to each other as the sensor pack 300 isbeing rotated by the indexing disk 30. As a result, information, such ascalibration and production data, contained on the conductive label 326can be transmitted via the probes 168 to the flex circuit 156, which inturn couples the data to the electronic circuitry on the circuit boardassembly 42 via an elastomeric connector 174. This information can thenbe used by the electronics assembly 62 to calibrate the sensordispensing instrument 10, or can be displayed on the liquid crystaldisplay 64.

As best seen in FIG. 10, the elastomeric connector 174 is made of layersof silicon rubber extending from a top edge 176 to a bottom edge 178with alternate layers having conductive materials dispersed therein toconnect contacts on the top edge 176 to contacts on the bottom edge 178.When the upper case 18 and the lower case 24 are closed, the elastomericconnector 174 is compressed in the direction between the edges 176 and178 such that the contacts along the top edge 176 engage electroniccircuitry on the circuit board assembly 42 in the upper case 18, and thecontacts along the bottom edge 178 engage the contacts 166 on the flexcircuit 156 in the lower case 24. With the elastomeric connector 174 socompressed, low voltage signals can be readily transmitted between thecircuit board assembly 42 and the flex circuit 156 through theelastomeric connector 174.

The elastomeric connector 174 is held in position by a slotted housing180 on the guide block 182. In the preferred embodiment shown, theslotted housing 180 has a serpentine cross-section configured to allowthe connector 174 to compress when the upper case 18 and the lower case24 are closed, while still holding the elastomeric connector 174 whenthe upper case 18 and the lower case 24 are open. Alternatively, theslotted housing 180 may include inwardly projecting ridges that engagethe sides of the connector 174.

The disk drive mechanism 34 is affixed to the upper inside surface ofthe upper case 18. As best seen in FIG. 10, the disk drive mechanism 34is attached to the upper case by a plurality of mounting screws 184 thatengage posts (not shown) on the upper inside surface of the upper case18. The mounting screws 184 also pass through and secure the electronicsassembly 62, which is disposed between the disk drive mechanism 34 andthe upper case 18.

Although the disk drive mechanism 34 will be described in greater detailbelow, it should be noted that the disk drive mechanism 34 is configuredso as to permit the assembly and testing of its operation prior tomounting the disk drive mechanism 34 to the upper inside surface of theupper case 18. In other words, the disk drive mechanism 34 has a modulardesign that can be tested prior to final assembly of the sensordispensing instrument 10.

As best seen in FIGS. 13 and 14, the disk drive mechanism 34 comprises aguide block 182, a sensor actuator 40, a housing guide 186, a disk drivepusher 48, an indexing disk drive arm 50, a knife blade assembly 58, apuller handle 32, a cover mechanism 188, and a button release 66. Thehousing guide 186 is fixed to the upper surface 190 (as viewed in FIG.13) of the guide block 182 by one or more pins 192. The disk drivepusher 48 is supported on the housing guide 186 and the guide block 182in such a manner as to permit the disk drive pusher 48 to slidelaterally relative to the housing guide 186 and the guide block 182. Theknife blade assembly 58 is pivotally connected to the underside of thedisk drive pusher 48, and is guided by the housing guide 186 and theguide block 182. The indexing disk drive arm 50 is also connected to thedisk drive pusher 48, and is partially guided by the guide block 182.The puller handle 32 comprises an upper puller handle 194 and a lowerpuller handle 196 connected to each other by snap-press fittings 198that pass through holes 200 in the rear end 202 of the disk drive pusher48. In the preferred embodiment shown, the upper puller handle 194 andthe lower puller handle 196 each have a concaved, textured outer surface(i.e., the top and bottom surfaces of the puller handle 32) tofacilitate gripping of the puller handle 32 between the thumb and fingerof the user's hand. The cover mechanism 188 is affixed to the guideblock 182 with the disk drive pusher 48 and the housing guide 186disposed therebetween. The sensor actuator 40 is attached to the guideblock 182 and is engaged by the front end 204 of the disk drive pusher48 when the disk drive pusher 48 is in the testing position. The buttonrelease 66 is slidably connected to the cover mechanism 188 so as toengage the front end 204 of the disk drive pusher 48 when the disk drivepusher 48 is in the testing position.

In addition, an indexing disk 30 is rotatably secured to the disk drivemechanism 34 by a retainer disk 206 connected through the indexing disk30 and into guide block 182. As best seen in FIG. 14, the retainer disk206 has a pair of latch arms 208 that extend through a central hole 210in the indexing disk 30 and latch into an opening 212 in the guide block182. As mentioned above, the indexing disk 30 includes a plurality ofpins 44 protruding from the lower surface 214 thereof. These pins 44 areconfigured to engage notches 324 on the sensor pack 300 (see FIG. 4) soas to align and rotate the sensor pack 300 in accordance with theposition of the indexing disk 30. Hence, the pins 44 and the notches 324have the dual purpose of retaining the sensor pack 300 on the indexingdisk 30 so that the sensor pack 300 will rotate with the indexing disk30 and of positioning the sensor pack 300 in proper circumferentialalignment relative to the indexing disk 30.

As previously indicated, the disk drive pusher 48 is pulled away fromthe rear end 16 of the housing 12 (away from the testing end 14) by theuser manually exerting a pulling force on the puller handle 32 to movethe handle 32 from the standby position to the extended position. As thepuller handle 32 is pulled away from the rear end 22 of the upper case18, the disk drive pusher 48 is guided in a lateral direction by theguide block 182, the housing guide 186, and the cover mechanism 188. Asthe disk drive pusher 48 slides towards the rear end 22 on the uppercase 18, the indexing disk drive arm 50 causes the indexing disk 30 torotate.

The indexing disk drive arm 50 extends rearwardly from the disk drivepusher 48. The indexing disk drive arm 50 includes a plate spring 54made of spring type material such as stainless steel so as to bias thearm 50 outwardly from the disk drive pusher 48. A cam button 52 isaffixed to the distal end of the arm 50, and is configured to engage theupper surface 216 (as viewed in FIG. 13) of the indexing disk 30. Inparticular, the indexing disk drive arm 50 is bent so as to protrudedownwardly through a slot 218 in the guide block 182 such that the cambutton 52 projects outwardly from the surface thereof. The slot 218 isdesigned such that the indexing disk drive arm 50 and the cam button 52can move along the slot 218 as the disk drive pusher 48 is moved backand forth during the testing procedure. The slot 218 also prevents theindexing disk drive arm 50 from moving sideways with respect to the diskdrive pusher 48 (i.e., it provides lateral support to the indexing diskdrive arm 50).

As best seen in FIG. 13, the upper surface 216 of the indexing disk 30comprises a series of radially extending grooves 60 and a plurality ofcurvilinearly extending grooves 56. The cam button 52 is configured toride along these grooves 56 and 60 during the movement of the disk drivepusher 48. As the disk drive pusher 48 slides towards the rear end 22 ofthe upper case 18, the cam button 52 moves along one of thecurvilinearly extending grooves 56. This causes the indexing disk 30 torotate. In the preferred embodiment shown, there are ten radiallyextending grooves 60 and ten curvilinearly extending grooves 56 equallyspaced about the circumference of the indexing disk 30, with eachradially extending groove 60 being disposed between a pair ofcurvilinearly extending grooves 56. Accordingly, the movement of thedisk drive pusher 48 towards the rear end 22 on the upper case 18results in a 1/10^(th) rotation of the indexing disk 30.

As the puller handle 32 is pulled away from the rear end 16 of thehousing 12 to a fully extended position, the cam button 52 passes overan outer step 220 that separates the outer end 222 of the curvilinearlyextending groove 56 from the adjacent radially extending groove 60. Theouter step 220 is formed by the difference in depth between the outerend 222 of the curvilinearly extending groove 56 and the outer end 224of the adjacent radially extending groove 60. In particular, the outerend 224 of the radially extending groove 60 is deeper than the outer end222 of the curvilinearly extending groove 56. Thus, when the cam button52 moves from the curvilinearly extending groove 56 into the adjacentradially extending groove 60, the biasing force of the plate spring 54of the indexing disk drive arm 50 causes the cam button 52 to traveldownwardly past the outer step 220. The outer step 220 prevents the cambutton 52 from re-entering the outer end 222 of the curvilinearlyextending groove 56 when the direction of travel of the disk drivepusher 48 is reversed (as will be explained below).

Rotation of the indexing disk 30 causes the sensor pack 300 to likewiserotate so that the next available sensor cavity 304 is placed in astandby position adjacent to the testing end 14 of the housing 12. Thesensor pack 300 rotates with the indexing disk 30 because of theengagement of the notches 324 on the sensor pack 300 by the pins 44 onthe indexing disk 30. As explained above, each sensor cavity 304contains a disposable sensor 302 that is used during the glucose testingprocedure.

Further rearward movement of the disk drive pusher 48 is prevented by arear wall 226 on the guide block 182. In the preferred embodiment shown,the rear wall 226 includes a slotted housing 180 for holding theelastomeric connector 174 that connects the electronics assembly 62 tothe flex circuit 156 disposed in the lower case 24. An interior edge 228of the disk drive pusher 48 engages the rear wall 226 on the guide block182 when the disk drive pusher 48 is in the fully extended position (seeFIG. 6).

From the fully extended position, the puller handle 32 is then manuallypushed inwardly back past the standby position (FIG. 1) and into atesting position (FIG. 7). As previously indicated, the inward movementof the puller handle 32 causes the disk drive mechanism 34 to remove asensor 302 from the sensor pack 300 and place the sensor 302 into atesting position.

As best seen in FIGS. 13 and 14, the disk drive mechanism 34 includes aknife blade assembly 58 that is pivotally mounted to the disk drivepusher 48. The knife blade assembly 58 comprises a swing arm 230 havinga first end 232 that is pivotally connected to the disk drive pusher 48by a pair of pivot pins 234. A knife blade 36 is connected to the secondend 236 of the swing arm 230. The second end 236 of the swing arm 230also includes a first cam follower 238 and a second cam follower 240,each in the shape of a transversely extending post. The first camfollower 238 is configured to follow a pathway formed on one side of theknife blade assembly 58 by the guide block 182, the housing guide 186,and the cover mechanism 188. In particular, this pathway is formed by acam projection 242 on the housing guide 186 that forms an upper pathway244 between the cam projection 242 and the cover mechanism 188 and alower pathway 246 between the cam projection 242 and the guide block182. When the first cam follower 238 is disposed in the upper pathway244, the knife blade 36 is in the retracted position. On the other hand,when the first cam follower 238 is disposed in the lower pathway 246,then the knife blade 36 is in the extended position. The upper pathway244 and the lower pathway 246 are connected together at both ends of thecam projection 242 so as to form a continuous loop about which the firstcam follower 238 can travel.

The second cam follower 240 engages a cam spring 248 attached to thehousing guide 186. As will be explained below, the cam spring 248 guidesthe knife blade assembly 58 from the lower pathway 246 to the upperpathway 244 when the disk drive pusher 48 is initially pulled rearwardfrom standby position towards the extended position. The disk drivepusher 48 also comprises a spring 250 for biasing the knife blade 36towards the extended position when the disk drive pusher 48 is initiallypushed forward from the extended position towards the testing position.In the preferred embodiment shown, the spring 250 comprises a platespring that presses against the upper side of the swing arm 230.

As the puller handle 32 is manually pushed from the extended position tothe testing position, the disk drive pusher 48 is pushed laterallytowards the testing or front end 14 of the housing 12. As the disk drivepusher 48 begins to move forward, the spring 250 biases the swing arm230 downwardly towards the indexing disk 30 so that the first camfollower 238 engages a sloped surface 252 on the interior end 268 of thecam projection 242 and is forced into the lower pathway 246. This causesthe knife blade 36 to assume an extended position whereby the knifeblade 36 projects outwardly through a knife slot 46 in the indexing disk30 to pierce the protective foil 310 covering one of the sensor cavities304 and engage the notch 312 on the back end 308 of the sensor 302contained therein. As the disk drive pusher 48 continues to move towardsthe front end 20 of the upper case 18, the first cam follower 238continues along the lower pathway 246, thereby causing the knife blade36 to remain in the extended position projecting through the knife slot46 so that it will travel along the knife slot 46 and push the sensor302 forward out of the sensor cavity 304 and into a testing position atthe front end 14 of the housing 12. The sensor 302 is in the testingposition when the front end 306 of the sensor 302 projects out of thesensor opening 254 formed on the front end of the guide block 182. Whilein the testing position, the sensor 302 is prevented from being pushedback through the sensor opening 254 by the engagement of the knife blade36 against the notch 312 on the back end 308 of the sensor 302.

As the disk drive pusher 48 reaches the testing position, the front end204 of the disk drive pusher 48 simultaneously engages the sensoractuator 40 and the button release 66. In particular, the front end 204of the disk drive pusher 48 engages and pushes the button release 66outwardly so as to project upwardly from the upper surface of the uppercase 18. At the same time, the front end 204 of the disk drive pusher 48engages a contact pad 256 on the sensor actuator 40 so as to force thesensor actuator 40 downward. This downward motion causes a pair of metalcontacts 38 on the sensor actuator 40 to project into the sensor opening254 on the guide block 182 and engage the contacts 314 on the sensor 302for the glucose testing procedure. The metal contacts 38 also apply africtional force to the sensor 302 so that the sensor 302 does notprematurely fall out of the sensor opening 254 prior to completion ofthe glucose testing procedure. In the preferred embodiment shown, themetal contacts 38 are somewhat flexible and are made of stainless steel.The housing guide 186 includes support ribs 187 disposed adjacent to themetal contacts 38 so as to prevent the metal contacts 38 from bending.As explained above, the metal contacts 38 permit the transmission ofelectrical signals between the sensor 302 and the electronics assembly62 during the glucose testing procedure.

When the glucose testing procedure is complete, the button release 66 isdepressed to release the sensor 302 from the testing position. Thebutton release 66 has a sloped contact surface 258 that engages thefront end 204 of the disk drive pusher 48 at an angle. As the buttonrelease 66 is depressed, the sloped contact surface 258 slides along thefront end 204 of the disk drive pusher 48, thereby causing the diskdrive pusher 48 to move rearward from the testing position and into thestandby position. In the preferred embodiment shown, the disk drivepusher 48 is moved laterally a distance of 0.080 inches. The movement ofthe disk drive pusher 48 to the standby position also causes the frontend 204 of the disk drive pusher 48 to disengage from the contact pad256 on the sensor actuator 40, thereby allowing the sensor actuator 40to move away from and disengage the sensor 302. The sensor 302 can thenbe removed by tipping the front end 14 of the sensor dispensinginstrument 10 downwardly.

As mentioned above, when the disk drive pusher 48 is pushed from theextended position towards the testing position, the cam button 52 on theindexing disk drive arm 50 travels along one of the radially extendinggrooves 60 to prevent the indexing disk 30 and the sensor pack 300 fromrotating. The radially extending groove 60 includes a sloped portion 260that changes the depth of the groove 60. In particular, the slopedportion 260 decreases the depth of the radially extending groove 60 sothat the middle portion of the radially extending groove 60 is shallowerthan the curvilinearly extending grooves 56. The radially extendinggroove 60 also comprises an inner step 262 near its inner end 264 (i.e.,near the center of the indexing disk 30). The inner step 262 is formedalong the juncture of the inner end 264 of the radially extending groove60 and the inner end 266 of the curvilinearly extending groove 56. Asthe disk drive pusher 48 is pushed from the extended position towardsthe testing position, the cam button 52 travels up the sloped portion260 of the radially extending groove 60, past the inner step 262, andinto the adjacent curvilinearly extending groove 56. The biasing forceof the plate spring 54 of the indexing disk drive arm 50 causes the cambutton 52 to travel downwardly past the inner step 262. The inner step262 prevents the cam button 52 from re-entering the radially extendinggroove 60 when the direction of travel of the disk drive pusher 48 isreversed (as explained above in connection with the outward movement ofthe disk drive pusher 48).

As the disk drive pusher 48 reaches the testing position, the first camfollower 238 passes the exterior end 270 of the cam projection 242. Atthe same time, the second cam follower 240 passes over the end of thecam spring 248, which retracts upwardly and out of the way as the firstcam follower 238 nears the exterior end 270 of the cam projection 242.Once the first cam follower 238 has passed the end of the cam spring248, the cam spring 248 moves downwardly so as to engage and guide thesecond cam follower 240 upwardly when the direction of travel of thedisk drive pusher 48 is reversed and pulled outward towards the extendedposition. In particular, when the disk drive pusher 48 is subsequentlypulled outward towards the extended position, the cam spring 248 guidesthe second cam follower 240 upwardly so that the first cam follower 238enters the upper pathway 244 and the knife blade 36 is retracted.

As explained above, the disk drive pusher 48 is pulled outwardly toinitiate the testing procedure. During the outward motion of the diskdrive pusher 48, the cam button 52 on the indexing disk drive arm 50travels along one of the curvilinearly extending grooves 56 so as torotate the indexing disk 30. During this outward motion, the first camfollower 238 on the knife blade assembly 58 travels along the upperpathway 244. As a result, the knife blade 36 is retracted from the knifeslot 46 on the indexing disk 30 so that the indexing disk 30 is free torotate in response to action of the cam button 52 in the curvilinearlyextending groove 56. As the disk drive pusher 48 reaches the fullyextended position, the first cam follower 238 passes the interior end268 of the cam projection 242 and is guided into the lower pathway 246by the biasing force of the spring 250 on the swing arm 230 of the knifeblade assembly 58.

Prior to operating the sensor dispensing instrument 10, a sensor pack300 must first be loaded into the sensor dispensing instrument 10 if onehas not already been so loaded, or if all of the sensors 302 in thepreviously loaded sensor pack 300 have been used. To load a sensor pack300, the lower case 24 and the upper case 18 are opened by depressingthe latch 72 on the lower case 24. In the preferred embodiment shown,the opening of the lower case 24 and the upper case 18 causes theelastomeric connector 174 to separate from the contacts 166 on theautocal disk 158, thereby breaking the electrical connection between theautocal disk 158 and the electronics assembly 62. This causes anelectronic counter (which is part of the electronics assembly 62) thatkeeps count of the number of unused sensors 302 in the sensor pack 300to re-set to zero (0).

The opened housing 12 is then turned so that the lower surface 214 ofthe indexing disk 30 faces upwardly as shown in FIG. 3. A sensor pack300 is then placed on the indexing disk 30 by aligning the notches 324along the periphery of the sensor pack 300 with the pins 44 on theindexing disk 30. The lower case 24 is then pivoted on to the upper case18 so as to enclose the sensor pack 300 within the housing. Once thelower case 24 is secured to the upper case 18 by the latch 72, thesensor dispensing instrument 10 is ready for operation.

The following is a brief description of the operation of the sensordispensing instrument 10. First, the puller handle 32 is manually pulledfrom a standby position (FIG. 1) adjacent the rear end 16 of the housing12 to an extended position (FIG. 6) away from the rear end 16 of thehousing 12. The outward movement of the puller handle 32 causes thesensor dispensing instrument 10 to turn ON. The outward movement of thepuller handle 32 also causes the cam button 52 on the indexing diskdrive arm 50 to travel along one of the curvilinearly extending grooves56 on the upper surface 216 of the indexing disk 30 so as to rotate theindexing disk 30 1/10^(th) of a complete rotation. The rotation of theindexing disk 30 causes the sensor pack 300 to be rotated so that thenext one of the sensor cavities 304 is placed in a standby positionaligned with the testing end 14 of the housing 12. At the same time, theknife blade assembly 58 is retracted and moved towards the center of theindexing disk 30.

Next, the puller handle 32 is manually pushed inwardly from the extendedposition (FIG. 6) back past the standby position (FIG. 1) and into atesting position (FIG. 7). The inward movement of the puller handle 32causes the knife blade assembly 58 to pivot downwardly so that a knifeblade 36 pierces a portion of the protective foil 310 covering thesensor cavity 304 in the standby position and engages the sensor 302 inthe sensor cavity 304. As the puller handle 32 continues to move backtowards the housing 12, the knife blade assembly 58 forces the sensor302 out of the sensor cavity 304 and into a testing position at thefront end 14 of the housing 12. At the same time, the cam button 52 onthe indexing disk drive arm 50 travels along one of the radiallyextending grooves 60 to prevent the indexing disk 30 from rotating.

After the sensor 302 has been completely ejected from the sensor cavity304 and pushed into a testing position projecting out from the front end14 of the housing 12, the sensor actuator 40 engages the sensor 302 tohold the sensor 302 in the testing position and to couple the sensor 302to the electronics assembly 62. The front end 306 of the sensor is theninserted into a drop of blood to be tested, whereby the blood isanalyzed by the electronics assembly 62. The results of the analysis arethen displayed on the liquid crystal display 64 of the sensor dispensinginstrument 10.

Once the analysis of the blood is complete, the button release 66 on theupper case 18 is depressed so as to disengage the sensor actuator 40 andrelease the sensor 302, which can be disposed of by tipping the frontend 14 of the housing 12 downwardly.

While the invention has been described with reference to details of theillustrated embodiment, these details are not intended to limit thescope of the invention as defined in the appended claims. For example,the sensor dispensing instrument 10 can be used for testing fluids otherthan blood glucose. In fact, the sensor dispensing instrument 10 can beused in connection with the analysis of any type of chemistry fluid thatcan be analyzed by means of a reagent material.

1. A sensor dispensing instrument adapted to handle a sensor packcontaining a plurality of sensors, each of said plurality of sensorsbeing disposed in a sensor cavity on said sensor pack and enclosed by aprotective foil covering, said sensor dispensing instrument furtheradapted to perform a test using one of said plurality of sensors, saidsensor dispensing instrument comprising: an outer housing having a frontend and a rear end, said outer housing further comprising a sensor slotthrough which one of said sensors is disposed to conduct the test; amechanism generally disposed within the outer housing, said mechanismincluding an indexing disk for supporting and rotating said sensor pack,an indexing support for rotating said indexing disk, an ejectingmechanism to eject one of said sensors from said sensor cavity andthrough said sensor slot, and a puller handle for moving said indexingsupport and the ejecting mechanism; an electronics assembly generallydisposed in the outer housing, said electronic assembly adapted toperform the test and display test results; a sensor actuator generallydisposed adjacent to the sensor slot, said sensor actuator adapted toengage with a sensor disposed in said sensor slot, to connect tocontacts on the sensor, and to transmit electrical signals between thesensor and said electronics assembly; and a sensor release generallydisposed on a surface of the outer housing, said sensor release beingmoveable to disengage said sensor actuator from the sensor disposed inthe sensor slot, said sensor release being adapted to move said pullerhandle and being adapted to disengage the sensor actuator such that thesensor can be removed from the instrument, wherein the puller handle,the sensor release and sensor actuator are distinct and separatecomponents.
 2. The sensor dispensing instrument according to claim 1,wherein said puller handle is moveable between a testing positionadjacent to the rear end of the outer housing and an extended positionspaced outwardly from the rear end of the outer housing, and whereinsaid puller handle is moved from the testing position to the extendedposition to rotate said indexing disk, and is moved from the extendedposition to the testing position to puncture the covering and eject oneof said sensors from said sensor cavity and through said sensor slot. 3.The sensor dispensing instrument according to claim 2, wherein thepuller handle is moveable to a stand-by position, said stand-by positionbeing located between the testing position and the extended position,wherein the sensor release is moved so as to move the puller handle fromthe testing position to the stand-by position and release the sensorfrom the sensor slot.
 4. The sensor dispensing instrument according toclaim 1, wherein the mechanical mechanism further comprises a movabledisk drive pusher, said indexing support and said ejecting mechanismbeing mounted on said disk drive pusher, and said puller handle beingaffixed to a rear end of said disk drive pusher.
 5. The sensordispensing instrument according to claim 4, wherein the sensor actuatoris engaged by a front end of said disk drive pusher to cause the sensoractuator to engage the sensor disposed in the sensor slot, and furtherwherein the sensor release engages the front end of the disk drivepusher to cause the sensor actuator to disengage from the sensordisposed in the sensor slot.
 6. The sensor dispensing instrumentaccording to claim 5, wherein the sensor release is moveable in adirection perpendicular to the movement of the disk drive pusher, andsaid sensor release comprises a sloped surface configure to engage thefront end of the disk drive pusher at an angle so that the movement ofthe sensor release causes the disk drive pusher to move.
 7. The sensordispensing instrument according to claim 1, wherein the sensor releasecomprises a button that projects outwardly from the surface of the outerhousing, said button being depressed to disengage the sensor actuatorfrom the sensor disposed in the sensor slot.
 8. The sensor dispensinginstrument according to claim 1, wherein said electronics assemblycomprises a printed circuit board electrically connected to said sensoractuator, electrical components mounted on the printed circuit board forconducting electronic functions in response to electrical signals, atleast one button mounted on the printed circuit board for supplyingelectrical signals to the electrical components, and a liquid crystaldisplay mounted on the printed circuit board for displaying said testresults.
 9. The sensor dispensing instrument according to claim 8,wherein the electronics assembly further comprises a communicationinterface mounted on the printed circuit board for connecting the sensordispensing instrument to a separate electronic device.
 10. The sensordispensing instrument according to claim 8, wherein the electronicsassembly further comprises battery terminals mounted on the printedcircuit board for connecting to a battery, said battery for supplyingelectrical power to said electrical components.
 11. A sensor dispensinginstrument adapted to perform a test by using a fluid testing sensor,said fluid testing sensor being supplied by a disposable sensor packinserted into said sensor dispensing instrument, said sensor pack havinga plurality of sensor cavities covered by a protective covering, saidfluid testing sensor being enclosed in one of said sensor cavities priorto the performance of said test, said sensor dispensing instrumentcomprising: an outer housing having a front end and a rear end, saidouter housing further comprising an upper case and a lower case, saidupper case and said lower case being pivotally connected together nearthe rear end of the outer housing in a clam-like fashion to permit theouter housing to be opened to permit the insertion of the sensor pack; alatch disposed near the front end of the outer housing and adapted toconnect the upper case to the lower case so as to close said outerhousing after the insertion of said sensor pack; a sensor slot disposedat the front end of the outer housing, said sensor slot being adapted toreceive said fluid testing sensor, said fluid testing sensor projectingoutwardly through said sensor slot during the performance of said test;an indexing disk for supporting and rotating said sensor pack, saidindexing disk being rotatably mounted within said outer housing andcomprising a plurality of curvilinearly extending grooves and aplurality of radially extending grooves, each radially extending groovebeing disposed between an adjacent pair of curvilinearly extendinggrooves; a disk drive pusher generally disposed within said outerhousing for rotating the indexing disk and ejecting the fluid testingsensor from said sensor pack, said disk drive pusher being laterallymovable and comprising an indexing disk drive arm for rotating saidindexing disk, said indexing disk drive arm being adapted to engage oneof the curvilinearly extending grooves and the radially extendinggrooves, said disk drive pusher further comprising a knife bladeassembly for ejecting the fluid testing sensor from the sensor pack,said knife blade assembly having a knife blade adapted to puncture saidprotective covering and engage the fluid testing sensor so as to ejectsaid fluid testing sensor from said sensor cavity and through saidsensor slot; a puller handle generally disposed at the rear end theouter housing for moving said dish drive pusher, said puller handlebeing affixed to a rear end of the disk drive pusher, said puller handlebeing moveable between a testing position adjacent to the rear end ofthe outer housing and an extended position spaced outwardly from therear end of the outer housing, wherein said puller handle is moved fromthe testing position to the extended position to rotate said indexingdisk, and wherein said puller handle is moved from the extended positionto the testing position to puncture the foil covering and eject saidfluid testing sensor from said sensor cavity and through said sensorslot; an electronics assembly for performing the test and displayingtest results, said electronics assembly comprising a circuit board,electrical components mounted on the circuit board for conductingelectronic functions in response to electrical signals, a plurality ofbuttons mounted on the circuit board for supplying electrical signals tothe electrical components, a liquid crystal display mounted on theprinted circuit board for displaying said test results; a sensoractuator disposed within said outer housing adjacent to said sensor slotfor connecting the fluid testing sensor to the electronics assembly,said sensor actuator adapted to engage and hold said fluid testingsensor in said sensor slot when said puller handle is in the testingposition, said sensor actuator having metal contacts adapted to connectto contacts on the fluid testing sensor when said fluid sensor testingsensor is disposed in said sensor slot and when said puller handle is inthe testing position so as to transmit electrical signals between saidfluid testing sensor and the printed circuit board of said electronicsassembly; and a sensor release generally disposed on a surface of theouter housing, said sensor release being movable to disengage saidsensor actuator from the fluid testing sensor disposed in the sensorslot and permit said fluid testing sensor to be discharged from saidsensor slot and removed from the instrument, said sensor being adaptedto move the puller handle from the testing components, wherein thepuller handle, the sensor release and sensor actuator are distinct andseparate components.
 12. The sensor dispensing instrument according toclaim 11, wherein the puller handle is moveable to a stand-by position,said stand-by position being located between the testing position andthe extended position, wherein the metal contacts of said sensoractuator are disconnected from the contacts on said fluid testing sensorwhen said puller handle is moved from the testing position to thestand-by position, and further wherein said puller handle is moved fromsaid testing position to said stand-by position by the movement of thesensor release.
 13. The sensor dispensing instrument according to claim11, wherein the sensor actuator is engaged by a front end of said diskdrive pusher to cause the sensor actuator to engage the fluid testingsensor disposed in the sensor slot, and further wherein the sensorrelease engages the front end of the disk drive pusher to cause thesensor actuator to disengage from the fluid testing sensor disposed inthe sensor slot.
 14. The sensor dispensing instrument according to claim13, wherein the sensor release is moveable in a direction perpendicularto the movement of the disk drive pusher, and said sensor releasecomprises a sloped surface configure to engage the front end of the diskdrive pusher at an angle so that the movement of the sensor releasecauses the disk drive pusher to move.
 15. The sensor dispensinginstrument according to claim 11, wherein the sensor release comprises abutton that projects outwardly from the surface of the outer housing,said button being depressed to disengage the sensor actuator from thefluid testing sensor disposed in the sensor slot.
 16. A method ofoperating a sensor dispensing instrument adapted to handle a sensor packcontaining a plurality of sensors, each of said plurality of sensorsbeing disposed in a sensor cavity on said sensor pack and enclosed by aprotective covering, and said sensor dispensing instrument furtheradapted to perform a test using one of said plurality of sensors, saidsensor dispensing instrument comprising an outer housing having a sensorslot disposed therein through which one of said sensors is disposed toconduct the test, said sensor dispensing instrument further comprising amechanism having an indexing disk for supporting and rotating saidsensor pack, an indexing support for rotating said indexing disk, anejecting mechanism to eject one of said sensors from said sensor cavityand through said sensor slot, a puller handle and a sensor release, saidpuller handle being moveable between a testing position adjacent to arear end of the outer housing, an extended position spaced outwardlyfrom the rear end of the outer housing, and a stand-by position locatedbetween the testing position and the extended position, said methodcomprises the acts of: a) grasping said puller handle when said pullerhandle is in the stand-by position; b) pulling said puller handle fromthe stand-by position to the extended position so as to move saidindexing support; c) pushing said puller handle from the extendedposition to the testing position so as to move said disk indexingsupport and cause said ejecting mechanism to eject one of said sensorsfrom said sensor cavity and through said sensor slot; d) performing thetest by using the sensor disposed in said sensor slot; and e) activatingsaid sensor release to engage said indexing support and move the pullerhandle from the testing position to the stand-by position so as to causethe sensor to be released from the sensor slot, the puller handle andthe sensor release being distinct and separate components.
 17. Themethod of claim 16, wherein the sensor dispensing instrument furthercomprises a sensor actuator generally disposed adjacent to the sensorslot and adapted to engage with a sensor disposed in said sensor slotwhen said puller handle is in the testing position, and act (c) includesengaging said sensor actuator with the sensor disposed in said sensorslot, and includes disengaging said sensor actuator from said sensordisposed in said sensor slot.
 18. The method of claim 16, wherein thesensor release comprises a button, and the act of activating the sensorrelease in act (e) comprises depressing said button.
 19. The sensordispensing instrument according to claim 1, wherein the protectivecovering is foil.
 20. The sensor dispensing instrument according toclaim 11, wherein the protective covering is foil.
 21. The method ofclaim 16, wherein the protective covering is foil.
 22. The method ofclaim 16, wherein the sensor release comprises a button that projectsoutwardly from the surface of the outer housing, said button beingdepressed to disengage the sensor actuator from the sensor disposed inthe sensor slot.
 23. The method of claim 16, wherein the grasping ofsaid puller handle is between a finger and a thumb of a user hand. 24.The sensor dispensing instrument according to claim 1, wherein thesensor release comprises a button that projects outwardly from thesurface of the outer housing, said button being adapted to be depressedso as to disengage the sensor actuator from the sensor disposed in thesensor slot.
 25. The sensor dispensing instrument according to claim 2,wherein the sensor release comprises a button that has a sloped contactsurface that engages a front end of the puller handle, the slopedcontact surface configured to slide along the front end of the pullerhandle thereby moving the puller handle from the testing position into astandby position so as to disengage the sensor actuator from the sensordisposed in the sensor slot.
 26. The sensor dispensing instrumentaccording to claim 25, wherein the standby position is between thetesting position and the extended position.
 27. The sensor dispensinginstrument according to claim 25, wherein the button is configured to bedepressed in a direction perpendicular to the direction of movement ofthe puller handle.